SWI-Prolog is a comprehensive Prolog environment. Its development
started in 1987 and has been driven by real-world applications.
SWI-Prolog is widely used in research, education, and commercial 
applications.

swi-prolog is build without BerkeleyDB support at the moment (too
experimental and won't build) and without GMP support. If you want 
GMP support with swiprolog, you need to build GMPlib (there is 
currently no build script at SlackBuilds.org from http://gmplib.org/ 
and run the script with  GMP=yes ./swi-prolog.SlackBuild
